Logarithmic mathematical morphology: a new framework adaptive to illumination changes

A new set of mathematical morphology (MM) operators adaptive to illumination changes caused by variation of exposure time or light intensity is defined thanks to the Logarithmic Image Processing (LIP) model. This model based on the physics of acquisition is consistent with human vision. The fundamental operators, the logarithmic-dilation and the logarithmic-erosion, are defined with the LIP-addition of a structuring function. The combination of these two adjunct operators gives morphological filters, namely the logarithmic-opening and closing, useful for pattern recognition. The mathematical relation existing between ``classical'' dilation and erosion and their logarithmic-versions is established facilitating their implementation. Results on simulated and real images show that logarithmic-MM is more efficient on low-contrasted information than ``classical'' MM

A Pseudo-logarithmic Image Processing Framework for Edge Detection

Abstract. The paper presents a new [pseudo-] Logarithmic Model for Image Processing (LIP), which allows the computation of gray-level ad-dition, substraction and multiplication with scalars within a fixed gray-level range [0;D] without the use of clipping. The implementation of Laplacian edge detection techniques under the proposed model yields superior performance in biomedical applications as compared with the classical operations (performed either as real axis operations, either as classical LIP models).

Functional Asplund's metrics for pattern matching robust to variable lighting conditions

In this paper, we propose a complete framework to process images captured under uncontrolled lighting and especially under low lighting. By taking advantage of the Logarithmic Image Processing (LIP) context, we study two novel functional metrics: i) the LIP-multiplicative Asplund's metric which is robust to object absorption variations and ii) the LIP-additive Asplund's metric which is robust to variations of source intensity and exposure-time. We introduce robust to noise versions of these metrics. We demonstrate that the maps of their corresponding distances between an image and a reference template are linked to Mathematical Morphology. This facilitates their implementation. We assess them in various situations with different lightings and movements. Results show that those maps of distances are robust to lighting variations. Importantly, they are efficient to detect patterns in low-contrast images with a template acquired under a different lighting

Miniature holistic displacement sensor by immersion diffractive interferometry

International audienceHigh interference contrast is obtained in a miniature dual-grating transmission displacement sensor submitted to an essentially uniform light flood of arbitrary polarization with multifunctional liquid film between gratings

Détection des conditions de visibilité et estimation de la distance de visibilité par vision embarquée

Dans cet article, nous présentons des méthodes de mesure de la visibilité atmosphérique à l'aide de caméras embarquées, dans le but de réaliser des aides à la conduite. Une analyse fonctionnelle des sources de perte de visibilité conduit à discerner différents types d'applications ainsi que des contraintes de choix et d'emplacement pour les capteurs. Une modélisation des effets du brouillard permet de définir différentes distances de visibilité et de construire les méthodes correspondantes de mesure en temps réel. Des résultats de mesure de visibilité sur images réelles permettent d'évaluer le travail réalisé

Sharp Plasmon-Mediated Resonant Reflection From an Undulated Metal Layer Sharp Plasmon-Mediated Resonant Reflection From an Undulated Metal Layer

International audienceIEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. Abstract: A close-to-the-theoretically-largest TM resonant reflection of a free-space wave from a free-standing undulated gold layer immersed in a liquid host medium is demonstrated experimentally. It is mediated by the grating-excited long-range plasmon mode propagating along the continuous metal film with particularly low loss

Information Retrieval from Unsegmented Broadcast News Audio

International audienceThis paper describes a system for retrieving relevant portions of broadcast news shows starting with only the audio data. A novel method of automatically detecting and removing commercials is presented and shown to increase the performance of the system while also reducing the computational effort required. A sophisticated large vocabulary speech recogniser which produces high-quality transcriptions of the audio and a window-based retrieval system with post-retrieval merging are also described. Results are presented using the 1999 TREC-8 Spoken Document Retrieval data for the task where no story boundaries are known. Experiments investigating the effectiveness of all aspects of the system are described, and the relative benefits of automatically eliminating commercials, enforcing broadcast structure during retrieval, using relevance feedback, changing retrieval parameters and merging during post-processing are shown. An Average Precision of 46.8%, when duplicates are scored as irrelevant, is shown to be achievable using this system, with the corresponding word error rate of the recogniser being 20.5%

General Adaptive Neighborhood Image Restoration, Enhancement and Segmentation

12 pagesInternational audienceThis paper aims to outline the General Adaptive Neighborhood Image Processing (GANIP) approach [1–3], which has been recently introduced. An intensity image is represented with a set of local neighborhoods defined for each point of the image to be studied. These so-called General Adaptive Neighborhoods (GANs) are simultaneously adaptive with the spatial structures, the analyzing scales and the physical settings of the image to be addressed and/or the human visual system. After a brief theoretical introductory survey, the GANIP approach will be successfully applied on real application examples in image restoration, enhancement and segmentation

Automatic Classification of Queries by Expected Retrieval Performance

International audienceThis paper presents a method for automatically predicting a degree of average relevance of a retrieved document set returned by a retrieval system in response to a query. For a given retrieval system and document collection, prediction is conceived as query classification. Two classes of queries have been defined: easy and hard. The split point between those two classes is the median value of the average precision over the query collection. This paper proposes several classifiers that select useful features among a set of candidates and use them to predict the class of a query. Classifiers are trained on the results of the systems involved in the TREC 8 campaign. Due to the limited number of available queries, training and test are performed with the leave-one-out and 10-fold cross-validation methods. Two types of classifiers, namely decision trees and support vector machines provide particularly interesting results for a number of systems. A fairly high classification accuracy is obtained using the TREC 8 data (more than 80% of correct prediction in some settings)